Haematology-Derived Inflammatory Markers in French Bulldogs with Brachycephalic Obstructive Airway Syndrome

Brachycephalic obstructive airway syndrome (BOAS) is a chronic obstructive respiratory disorder that raises significant welfare concerns for affected breeds. Canine BOAS can be compared to obstructive sleep apnoea (OSAS) in humans, as both disorders cause intermittent hypoxia which can alter the metabolic, immune and inflammatory systems. Haematological markers and their ratios can be used to access systemic inflammatory status and have been proved to be changed in patients with OSAS. In this retrospective study we compared haematological parameters and haematology-derived inflammatory markers between French Bulldogs diagnosed with BOAS and nonbrachycephalic dogs. The study involved a total of 30 client-owned dogs; the BOAS group consistent of 15 French Bulldogs that were evaluated as BOAS grade 2 and 3 and the control group consisted of 15 healthy non-brachycephalic dogs. Significant differences (p < 0.05) were observed in several investigated markers. BOAS patients had a significantly higher platelet count, platelet-to-lymphocyte ratio and systemic immuneinflammation index, as well as significantly lower lymphocyte-to-monocyte ratio values compared to non-brachycephalic dogs, which suggest the presence of systemic inflammation in BOAS-affected dogs. Our study provides new insights into the inflammatory state in BOAS affected French Bulldogs and highlights the need for further studies in larger groups of BOAS patients of different brachycephalic breeds including evaluation of the effects of surgical treatment on haematology-derived inflammatory markers.